<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // 绑定键盘事件生效的有哪些? 
        // document window  表单 
        document.onkeydown = function(event){
            var e = event || window.event;
             console.log(e);
            // console.log(e.key);
            // console.log(e.keyCode); // 返回的键的ascii码  
            // if(e.keyCode == 65){
            //     alert('您按下了a键')
            // }

            // 判断是否按下了ctrl + shift +a 

            // e.ctrlKey 如果true 说明按下了ctrl键 
            // e.shiftKey 如果true 说明按下了shift键 

            if(e.keyCode === 69 && e.ctrlKey &&  e.altKey ){
                alert('您按下了ctrl + alt +e')
            }

        }
    </script>
</body>
</html>